The present invention relates generally to optical lenses, and more particularly to externally-worn optical lenses which are designed to minimize glare, contrast sensitivity, chromatic and spherical aberrations and color distortion while maximizing visual acuity and blockage of a predetermined percentage of light wavelength transmission throughout the blue light spectrum.
The incidence of cataracts and macular degeneration is increasing worldwide. Causes for this condition range from atmospheric ozone depletion, which increases exposure to damaging electromagnetic radiation, to exposure to violet and blue light wavelengths, ultraviolet A and B wavelengths, and infrared wavelengths, all of which damage vulnerable eye components. A specific potentially dangerous situation occurs where a synthetic intraocular lens implant is surgically placed in the eye of a patient after removal of the crystalline lens. In particular, as the human lens ages, it is subject to nuclear sclerosis, known as “brunescent cataract,” which, because of its color, blocks at least a portion of blue light entry generally up to 450 nm. In fact, human studies show that a normal 53 year old crystalline lens transmits only 10-50 percent of visible blue light to the retina. Because this blue light can be quite damaging to the retina, such natural blockage is highly desired. If this natural lens becomes generally inoperative because of critical cataract growth, it typically is surgically replaced within a lens implant. Present lenses employed for implant, however, do not block wavelengths above 400 nm, thus resulting in 100% passage of blue light (400 nm to 510 nm) to the retina and resulting retina exposure to potential hazard.
In view of the retinal hazard caused by wavelength transmission through such an implanted lens, it is apparent that a need is present for intraocular protection against damaging blue light hazards, with such protection extending to blockage of ultraviolet and infrared wavelength transmissions as advisable. Accordingly, the primary object of the present invention is to provide an implantable synthetic replacement lens wherein such a lens blocks at least a significant portion the wavelength transmission between about 400 and 510 nm.
Another object of the present invention is to provide an implantable synthetic replacement lens wherein, in addition to blocking a significant portion thereof of visible wavelength transmission between about 400 and 510 nm, the lens blocks ultraviolet A and B and infrared wavelength transmissions.
Yet another object of the present invention is to provide methodology whereby a patient is provided with protection from ocularly damaging wavelength transmission by implantation of a synthetic intraocular refractive lens.
In addition, many people wear external eye wear, such as eyeglasses, sunglasses, goggles and contact lenses. Typically, these types of external eye wear provide inadequate blue-blocking protection for the eye. For example, although sunglasses and goggles are often polarized to block some light, they do not adequately block wavelength transmission between 400 and 510 nm, ultraviolet A and B, and infrared wavelength transmission. Adding such protection could advantageously allow a wearer to selectively protect their eyes, or remove the eyewear when blocking of such light is hazardous. Therefore, it is an object of the present invention to extend this type of protection to all forms of external eye wear.
These and other objects of the present invention will become apparent through the description thereof which now follows.